A microwave-assisted facile regioselective Fischer indole synthesis and antitubercular evaluation of novel 2-aryl-3,4-dihydro-2H-thieno[3,2-b]indoles

N-Cyclo-hexyl-2-(5-meth-oxy-1H-indol-3-yl)-2-oxoacetamide

In the title compound, C(17)H(20)N(2)O(3), the cyclo-hexane ring adopts a chair conformation. In the crystal, inter-molecular N-H⋯O hydrogen bonds link the mol-ecules into layers parallel to the ac plane.

A microwave-assisted, facile, regioselective Friedländer synthesis and antitubercular evaluation of 2,9-diaryl-2,3-dihydrothieno-[3,2-b]quinolines

A series of 2,9-diaryl-2,3-dihydrothieno[3,2-b]quinolines have been synthesized regioselectively by Friedländer annulation of 5-aryldihydro-3(2H)-thiophenones and 2-aminobenzophenones in the presence of trifluoroacetic acid in good yields under microwave irradiation at 100 degrees C. The 2,9-diaryl-2,3-dihydrothieno[3,2-b]quinolines were screened for in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Rv (MTB) and multi-drug resistant M. tuberculosis (MDR-TB). Among the 17 compounds screened, 7-chloro-2-(2,4-dichlorophenyl)-9-phenyl-2,3-dihydrothieno-[3,2-b]quinoline and 7-chloro-2-(3-nitrophenyl)-9-phenyl-2,3-dihydrothieno[3,2-b]quinoline display maximum activity with MIC of 0.90 and 0.95 muM against MTB and MDR-TB respectively.

A highly atom economic, chemo-, regio- and stereoselective synthesis and evaluation of spiro-pyrrolothiazoles as antitubercular agents

The 1,3-dipolar cycloaddition of azomethine ylides derived from substituted isatins and 1,3-thiazolane-4-carboxylic acid to a series of 1-methyl-3,5-bis[(E)-arylmethylidene]-tetrahydro-4(1H)-pyridinones afforded novel spiro-pyrrolothiazoles chemo-, regio- and stereoselectively in quantitative yields. These compounds were screened for their in vitro activity against Mycobacterium tuberculosis H37Rv (MTB) and multi-drug resistant M. tuberculosis (MDR-TB) using agar dilution method. Among the synthesized compounds, spiro[5.3'']-5''-nitrooxindole-spiro-[6.3']-1'-methyl-5'-(2,4-di-chlorophenylmethylidene)tetrahydro-4'(1H)-pyridinone-7-(2,4-dichlorophenyl)tetra-hydro-1H-pyrrolo[1,2-c][1,3]thiazole (9k) was found to be the most active with a minimum inhibitory concentration (MIC) of 0.6microM against MTB and MDR-TB.

L-proline-catalysed facile green protocol for the synthesis and antimycobacterial evaluation of [1,4]-thiazines

A series of ethyl 6-(4-chlorobenzoyl)-1,1-dioxo-3,5-diaryl-1,4-thiazinane-2-carboxylates was prepared in good yields (72-90%) from the reaction of ethyl 2-[(2-oxo-2-arylethyl)sulfonyl]acetate, substituted aromatic aldehydes and amines in presence of green catalyst, L-proline. These compounds were evaluated for in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Rv (MTB), multi-drug resistant M. tuberculosis (MDR-TB) and Mycobacterium smegmatis (MC(2)) using agar dilution method. Ethyl 6-(4-chlorobenzoyl)-3,5-di(4-nitrophenyl)-1,1-dioxo-1,4-thiazinane-2-carboxylate was found to be the most promising compound (MIC: 0.68 microM) active against MTB and MDR-TB.

An atom economic synthesis and antitubercular evaluation of novel spiro-cyclohexanones

The 1,3-dipolar cycloaddition of azomethine ylides derived from acenaphthenequinone and alpha-amino acids viz. sarcosine, phenylglycine, 1,3-thiazolane-4-carboxylic acid and proline to a series of 2,6-bis[(E)-arylmethylidene]cyclohexanones afforded novel spiro-heterocycles chemo-, regio- and stereoselectively in quantitative yields. These compounds were screened for their in vitro activity against Mycobacterium tuberculosis H37Rv (MTB) using agar dilution method. Two compounds, 4-(2,4-dichlorophenyl)-5-phenylpyrrolo(spiro[2.2'']acenaphthene-1''-one)spiro[3.2']-6'-(2,4-dichlorophenylmethylidene)cyclohexanone (4i) and spiro[5.2'']acenaphthene-1''-onespiro[6.2']-6'-(2,4-dichlorophenylmethylidene)cyclohexanone-7-(2,4-dichlorophenyl)tetrahydro-1H-pyrrolo[1,2-c][1,3]thiazole (5i) display maximum activity in vitro with a MIC value of 0.40microg/mL against MTB and were 4 and 15.6 times more potent than ethambutol and pyrazinamide, respectively.